The Relationship Between Thyroid-Stimulating Hormone Levels and Outcomes From SELECT

Clinical Pearls

Steven I. Sherman, MD, associate vice-provost for Clinical Research, professor and chair, Endocrine Neoplasia and Hormonal Disorders, MD Anderson Cancer Center, discusses the relationship between thyroid-stimulating hormone levels and outcomes from the phase III SELECT trial. The SELECT trial looked at lenvatinib versus placebo for the treatment of patients with relapsed/refractory differentiated thyroid cancer.

• One side effect of lenvatinib is that it alters the absorption of levothyroxine.
• It was anticipated that this effect would raise serum TSH levels. This could be significant because TSH can stimulate the growth of thyroid cancer.
• Though many patients developed increased TSH levels and needed increased dosing of thyroid hormone throughout the SELECT trial, the efficacy of lenvatinib was not affected.